The present invention relates to a purging apparatus for conducting an air purge required when an equipment such as a split type air conditioner is installed or repaired, and to a to-be purged apparatus and a purging method.
Conventionally, in the case of a split type air conditioner, since its connecting pipes and its indoor heat exchanger are exposed to atmosphere and air exists therein, a purging operation for removing the air is required. Such an operation will be explained with reference to FIG. 25. In a general split type air conditioner, before it is installed, a refrigerant gas is charged in an outdoor unit 101. The outdoor unit 101 and an indoor unit 102 are connected using connecting pipes 103 by installing operation. After installing operation is completed, in order to remove the air existing in an indoor heat exchanger 104 and the connecting pipes 103, the refrigerant gas in the outdoor unit 101 is sent out from a 2-way valve 105 little by little to push out the air in the indoor heat exchanger 104 and the connecting pipes 103 to discharge the air from a service port 107 of a 3-way valve 106 which is another connection valve mounted to the outdoor unit 101.
Japanese Patent Application No. H9-133440 discloses a similar example of the purging method in a system using a refrigerant including hydro fluorocarbon as a working fluid. Constituent members having the same functions as those shown in FIG. 25 are designated by the same reference numerals, and explanations thereof will be omitted. As shown in FIG. 26, after the separate air conditioner is connected, a container 108 into which hydrocarbon gas having a pressure higher than atmospheric pressure is charged is connected to the service port 107. Another service port 110 capable of opening into atmosphere is mounted also to a connection 3-way valve 109 of the other outdoor unit. With this structure, the hydrocarbon gas is released into the system to push the inside air, and the service port 110 is opened into the atmosphere to conducting the air purge.
There is another method to remove non-condensation gas such as air by connecting a vacuum pump to the service port 107 in FIG. 25 to forcibly remove the inside air. This method is generally carried out in the installing and repairing operation.
However, according to the above-described conventional methods, the refrigerant gas which is sent out as an exchanger gas is discharged out into atmosphere at the time of air purge, which may adversely affect global environment such as global warming. Further, when the replacing gas(hereinafter sometimes referred to as exchanger gas) is a flammable material or a toxic material, there is a problem that such gas must be discharged out, which may bring a worker and the circumferential environment into an extremely dangerous state.
In view of the above problems, it is an object of the present invention to provide a purging method, a purging unit and a to-be purged unit which has a simple structure and which does not discharge the refrigerant gas to atmosphere when an equipment such as a split type air conditioner requiring the air purge is installed.
According to claim 1, a purging method uses: a to-be purged apparatus having a to-be purged room with two or more valve openings capable of connecting to a main circuit or to a circuit other than the main circuit; and a purging apparatus having a replacing gas container into which a replacing gas to be exchanged for a to-be purged gas is previously charged and a gas collecting container for collecting gas including the to-be purged gas, one of the valve openings of the to-be purged room and the replacing gas container can be connected with each other, and the other valve opening of the to-be purged room and the gas collecting container can be connected with each other; the method comprising the steps of: sending the replacing gas in the replacing gas container, thereby pushing out the to-be purged gas in the to-be purged apparatus; and collecting the to-be purged gas into the gas collecting container.
With this structure, by exchanging air in the to-be purged room to the replacing gas, it is possible to remove non-condensation gas such as air which may adversely affect the actual operation of the equipment. Further, a room of the replacing gas used for purging is collected into the gas collecting container together with the to-be purged gas and therefore, it is possible to prevent a material causing global warming such as refrigerant gas or a dangerous material such as flammable gas from being discharged into atmosphere.
According to claim 2, a to-be purged apparatus comprises a to-be purged room for exchanging a gas therein for a replacing gas, the to-be purged room having a valve opening for connecting with a main circuit and two or more valve openings for connecting with circuit other than the main circuit.
With this structure, the to-be purged apparatus has two or more valve openings, and if an arbitrary valve opening is selected and connected to the purging apparatus, the purging method in claim 1 can be realized.
According to claim 3, a purging apparatus comprises a replacing gas container into which a replacing gas to be exchanged for to-be purged gas is previously charged, and a gas collecting container for collecting gas including the to-be purged gas, one of valve openings of the to-be purged room and the replacing gas container, and other valve opening of the to-be purged room and the gas collecting container are capable of connecting with each other.
With this structure, there are provided the container in which the replacing gas to be exchanged for the to-be purged gas is charged and the gas collecting container for collecting the to-be purged gas partially having the replacing gas, it is possible to realize the purging method of claim 1 which does not discharge the replacing gas.
According to claim 4, the number of the valve openings is two, and the two valve openings are mounted at opposite ends of a pipe requiring purging operation. With this structure, since the farthest opposite ends among the to-be purged paths are provided with valve openings for connection with the purging apparatus, the gas can be exchanged without forming a stagnation of to-be purged gas in the to-be purged paths and therefore, the apparatus can be constituted using the minimum number of valves.
According to claim 5, the purging apparatus further comprises gas moving means for moving the replacing gas or the to-be purged gas. With this structure, gas in the system can easily be moved toward the gas collection container by providing the gas moving means in the path of the to-be purged room and therefore, it is unnecessary to excessively increase the pressure of the replacing gas in the replacing gas container for moving the replacing gas by the pressure difference, it is unnecessary to charge the replacing gas excessively, and a container and piping device which can withstand a high pressure are unnecessary.
According to claim 6, the gas collecting container is provided therein with a replacing gas adsorbing material inside for adsorbing the replacing gas and/or replaced gas(such as air or so). With this structure, since the replacing gas adsorbing material is contained in the gas collecting container, the replacing gas sent into the gas collecting container together with the to-be purged gas and adsorbed in the adsorbing material. Therefore, the pressure in the collection container is reduced by the adsorbed amount of the replacing gas, the internal pressure of the gas collecting container is correspondingly reduced, the to-be purged gas can be collected into the gas collecting container more easily and the purging operation can be carried out effectively.
According to claim 7, the gas collecting container is evacuated into vacuum or is depressurized. With this structure, since the pressure at the gas collecting container side is lowered, the pressure difference is generated and the replacing gas can be moved from the replacing gas container without using some devices of the replacing gas such as air pump, it is possible to carry out the purging operation without complicating the apparatus.
According to claim 8, a volume of the gas collecting container is variable. With this structure, since the volume of the gas collecting container is variable, the to-be purged gas in an amount pushed out by the replacing gas flows in the gas collecting container, the pressure in the container does not rise by the inflow gas and therefore, it is possible to smoothly collect the pushed out gas. Further, the gas collecting container need not be a pressure container, and the purging operation can be carried out smoothly with a simple apparatus.
According to claim 9, a volume of the replacing gas container is variable. With this structure, since the volume of the replacing gas container is variable, when the replacing gas therein is sent out by the purging operation by means of the gas moving means or the like, pressure in the container can be controlled so as to keep enough high pressure to push out the replacing gas and not become negative pressure. Therefore, opposite pressure is not applied to the gas movement, and the purging operation can be carried out smoothly.
According to claim 10, the same fluid as the gas in the main circuit is used as the gas. With this structure, since the replacing gas is the same as the working fluid, the gas does not affect the operation and performance of the equipment. Further, since a foreign material is not mixed, it is possible to enhance the reliability of the equipment.
According to claim 11, the purging apparatus further includes a volume control device capable of varying a volume of the replacing gas container. With this structure, it is unnecessary to dispose an expensive equipment such as the gas pump, the replacing gas can easily be sent out by the replacing gas container alone and therefore, it is possible to provide an inexpensive apparatus. According to claim 12, the purging apparatus further includes a value variable driving apparatus capable varying a volume of the gas collecting container. With this structure, it is unnecessary to dispose an expensive equipment such as the gas moving apparatus, the replacing gas can be easily collected and moved by the gas collecting container alone and therefore, it is possible to provide an inexpensive apparatus.
According to claim 13, a purging apparatus comprises a replacing gas room, a collection gas room and partitioning means for deviding both rooms separately, wherein the partitioning means varies the volumes of both rooms correspondingly. With this structure, the replacing gas container and the gas collecting container commonly use the container space, and if the replacing gas is sent out, a volume of the replacing gas container is reduced and a volume of the gas collecting container is increased by the same amount. Therefore, a volume of one of the replacing gas container and the gas collecting container suffices as a container space as the purging apparatus. Therefore, the apparatus can be made smaller, and the apparatus can easily be carried to a place where the purging operation should be carried out.
According to claim 14, the replacing gas room and the collection gas room are integrally formed in a container having a constant cross section, and the partitioning means is slidably movable. With this structure, if the partition mean between the replacing gas container and the gas collecting container is a thing like a piston which can be moved in its longitudinal direction, it is possible to provide a purging apparatus which can easily be worked and assembled in an actual manufacture of the apparatus.
According to claim 15, the purging apparatus according to claim 13 or 14, further comprises volume variable means for moving the partitioning means. With this structure, the purging operation can be carried out without the expensive gas moving means, sending the replacing gas and collecting the to-be purged gas can be conducted simultaneously. Therefore, the purging operation can be carried out effectively with a simpler apparatus.
According to claim 16, a pressure of the replacing gas is set to a value between 0.0 MPa and 0.2 Mpa at the temperature. Generally refrigerant for an air conditioner may be liquefied gas. According to the high pressure law, if pressure of liquefied gas is lower than 0.2 MPa, the replacing gas container need not be a pressure container. Therefore, the purging apparatus or the replacing gas container can be constructed by a simpler and inexpensive container. Further, the container can be lightened and can be carried easily.
According to claim 17, the purging apparatus further comprises pressure detecting means for detecting pressure in the replacing gas. With this structure, when the replacing gas is charged into the replacing gas container from, e.g., a gas cylinder before the purging operation, the gas can be charged while checking the charging pressure. Therefore, it is possible to prevent the excessive charging of the replacing gas, and to charge the replacing gas in a appropriate amount.
According to claim 18, the replacing gas container or the replacing gas room is provided with inflow pressure control means capable of controlling inflow pressure of the replacing gas to be charged. With this structure, by fixing the flowing pressure to the replacing gas container to a predetermined value, it is possible to automatically prevent the excessive charging, and to avoid the operation mistake at the time of charging.
According to claim 19 the replacing gas container or the replacing gas room is connected to the to-be purged apparatus through water removing means. With this structure, even if moisture is included in the replacing gas, it is possible to remove the moisture before the replacing gas is sent to the to-be purged apparatus. Therefore, it is possible to prevent the replacing gas including moisture from entering the air conditioner, and to prevent a trouble such as ice choke.
According to claim 20, the replacing gas container or the replacing gas room is connected to the to-be purged apparatus through a check valve for preventing backward flow of the gas. With this structure, it is possible to prevent the replacing gas which is once sent out of the replacing gas container from flowing backward into the replacing gas container and thus, to-be purged gas can be pushed out smoothly flow of the replacing gas in a constant direction.
According to claim 21, the gas collecting container or the collection gas room is connected to the to-be purged apparatus through a check valve for stopping the movement of gas in a direction from the to-be purged apparatus toward the gas collecting container or the collection gas room. With this structure, it is possible to prevent the to-be purged gas which is once collected from flowing reversibly toward the to-be purged room and thus, residue of the to-be purged gas can be reduced by keeping the flow of the to-be purged gas in a constant direction.
According to claim 22, a connection room of the replacing gas container or the replacing gas room with the to-be purged apparatus has a structure capable of sealing against atmosphere when the connection room is disconnected. With this structure, when the purging apparatus and the to-be purged apparatus are separated from each other after the purging operation, the replacing gas in the system should not flow out. For example, when the replacing gas includes flammable or toxic material, it is possible to provide a purging apparatus having a replacing gas container which can prevent the replacing gas from leaking and secure the safety.
According to claim 23, a connection room of the gas collecting container or the collection gas room with the to-be purged apparatus has a structure capable of sealing against atmosphere when the connection room is disconnected. With this structure, when the purging apparatus and the to-be purged apparatus are separated from each other after the purging operation, the replacing gas in the system should not flow out. For example, when the replacing gas includes flammable material or toxicity, it is possible to provide a purging apparatus having a gas collecting container which can prevent the replacing gas from leaking and secure the safety.
According to claim 24, a connection room of the to-be purged apparatus with the purging apparatus has a structure capable of sealing against atmosphere when the connection room is disconnected. With this structure, when the purging apparatus and the to-be purged apparatus are separated from each other after the purging operation, the replacing gas in the system should not flow out. For example, when the replacing gas includes flammable or toxic material, it is possible to provide a to-be purged apparatus which can prevent the replacing gas from leaking and secure the safety.
According to claim 25, the to-be purged gas that exists in the to-be purged room is air or gas including oxygen, a connection path between the gas collecting container or the collection gas room and the to-be purged apparatus is provided with oxygen gas detecting means, and the purging apparatus further comprises the first purge completion judging means for judging a completion of purging operation based on a signal from the oxygen gas detecting means. When the to-be purged gas is air in the air conditioner, if oxygen gas is continuously, intermittently or in the spot manner in the path connected to the collection gas cylinder, and if oxygen gas is not detected any more, it can be judged that gas in the to-be purged system is completely exchanged with the replacing gas. Therefore, more reliable purging operation can be carried out.
According to claim 26, the purging apparatus further comprises exchanger gas detecting means disposed in a connection path between the to-be purged apparatus and the gas collecting container or the collection gas room for detecting the replacing gas, and the second purge completion judging means for judging a completion of purging operation based on a signal from the replacing gas detecting means. With this structure, the replacing gas is continuously, intermittently or in a spot manner by the replacing gas detecting means disposed closer to the gas collecting container than the to-be purged room, and the replacing gas flowing into the gas collecting container is detected. Therefore, it is possible to confirm that gas in the to-be purged room is sufficiently exchanged to the replacing gas, and the completion of the purging operation can be judged reliable.
According to claim 27, the replacing gas is intermittently sent out from the replacing gas container or the replacing gas room. When the replacing gas is sent out continuously, to-be purged gas may stay in a certain part of the circuit of the to-be purged room, and there is a residue of the to-be purged gas in the system. Thereupon, by sending the replacing gas intermittently, the to-be purged gas staying is dispersed so as to prevent the gas from staying locally, and more reliable exchanging operation can be conducted.
According to claim 28, the replacing gas container or the replacing gas room is connected to one of connection valves of the to-be purged apparatus having a greater diameter.
With this structure, since the replacing gas is sent out in the form of gas, a pressure drop in the vicinity of the exit of the replacing gas container is smaller and exchanger gas can be sent out more smoothly when the gas is sent out from a larger valve opening than when the gas is sent out from a smaller valve opening. It is possible to prevent the generation of stagnation such as swirl which is prone to be generated when the diameter of the path is increased from thin pipe to thick pipe, and more effective gas exchange can be conducted.
According to claim 29, a flammable gas which does not generate harmful material when it is burned out is used as the replacing gas, and after the gas exchange is completed, the replacing gas in the to-be purged apparatus is burned.
With this structure, excessive exchanger gas in the to-be purged apparatus is burned outside, thereby evacuating and discharging the to-be purged apparatus, and the pressure therein can be reduced to substantially a constant pressure. Therefore, it is possible to control the replacing gas amount remaining in the to-be purged apparatus to approximately predetermined amount and thus, the amount of working fluid gas is not varied when a main circuit is utilized, and a designed capacity can be kept as it is.
According to claim 30, the purging apparatus further comprises pressure detecting means disposed in a path extending from the replacing gas container or the replacing gas room to the gas collecting container through the to-be purged apparatus for detecting pressure in the to-be purged room, and a sub-container connected to the path in parallel to the gas collecting container through valve.
With this structure, the replacing gas pressure in the to-be purged room can be adjusted with a simple structure, and it is possible to adjust the amount of the replacing gas remaining in the to-be purged apparatus due to the purging operation to a predetermined amount.
According to claim 31, the sub-container is evacuated into vacuum or is depressurized. With this structure, the adjusting region of the gas pressure in the to-be purged room can be enlarged, and it is possible to more accurately adjust the amount of exchanger gas remaining in the to-be purged apparatus due to the purging operation.